Protective Effects of 2-Methoxyestradiol on Acute Isoproterenol-Induced Cardiac Injury in Rats

Icariin inhibits cisplatin-induced ovarian toxicity via modulating NF-κB and PTEN/AKT/mTOR/AMPK axis

Cisplatin (CP) is a highly effective broad-spectrum chemotherapeutic agent for several solid tumors. However, its clinical use is associated with ovarian toxicity. Icariin (ICA) is a bioactive flavonoid of Epimedium brevicornum with reported protective activities against inflammation, oxidative stress and ovarian failure. This study aimed to explore the protective effects of ICA against CP-associated ovarian toxicity in rats. Rats were randomized into five groups and treated for 17 days: control, ICA (10 mg/kg/day, for 17 days. p.o.), CP (6 mg/kg, i.p. on days 7 and 14), CP + ICA (CP 6 mg/kg i.p. on days 7 and 14 and ICA 5 mg/kg p.o. daily), and CP + ICA (CP 6 mg/kg i.p. on days 7 and 14 and ICA 10 mg/kg p.o. daily). Our results indicated that ICA effectively improved ovarian reserve as indicated by attenuating CP-induced histolopathological changes and enhancing serum anti-müllerian hormone (AMH). Furthermore, co-administration of ICA with CP showed restoration of the oxidant-anti-oxidant balance in ovarian tissues, evidenced by decreased malondialdehyde (MDA) concentrations and elevated superoxide dismutase (SOD) and catalase (CAT) activities. Also, ICA suppressed ovarian inflammation as evidenced by down-regulation of the expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and nuclear factor kappa B (NF-κB). ICA inhibited ovarian apoptosis in CP-treated rats by down-regulation of CASP3 and Bax and up-regulation of Bcl-2 mRNA expression. Further, ICA enhanced PTEN, p-AKT, p-mTOR, and p-AMPKα expression. In conclusion, ICA possesses a protective activity against CP-induced ovarian toxicity in rats by exhibiting antioxidant, antiinflammatory, anti-apoptotic activities and modulating NF-κB expression and PTEN/AKT/mTOR/AMPK axis in ovarian tissues.

Liraglutide Protects Cardiomyocytes against Isoprenaline-Induced Apoptosis in Experimental Takotsubo Syndrome

Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy, characterized by an increased concentration of catecholamines, free radicals, and inflammatory cytokines, endothelial dysfunction, and increased apoptotic activity. High doses of isoprenaline are used in animal models to induce Takotsubo (TT)-like myocardial injury. The aim of the study was to investigate the antiapoptotic effects of liraglutide in experimental TTS and its role in the NF-κB pathway. Wistar rats were pretreated with liraglutide for 10 days, and on days 9 and 10, TT-like myocardial injury was induced with isoprenaline. After the sacrifice on day 11, hearts were isolated for histopathological and immunohistochemical analysis. Liraglutide reduced isoprenaline-induced cardiomyocyte apoptosis by decreasing cleaved caspase-3 (CC3), BCL-2-associated X protein (BAX), and NF-κB and increasing B-cell lymphoma/leukemia-2 (BCL-2). An increase in NF-κB in isoprenaline-treated rats was in positive correlation with proapoptotic markers (BAX and CC3) and in negative correlation with antiapoptotic marker BCL-2. Liraglutide increased BCL-2 and decreased NF-κB, BAX, and CC3, preserving the same correlations of NF-κB to apoptotic markers. It is concluded that liraglutide protects cardiomyocytes against isoprenaline-induced apoptosis in experimental TT-like myocardial injury through downregulation of the NF-κB pathway.

Surface entrenched β-sitosterol niosomes for enhanced cardioprotective activity against isoproterenol induced cardiotoxicity in rats

Cardiotoxicity (CT) is a severe condition that negatively impacts heart function. β-sitosterol (BS) is a group of phytosterols and known for various pharmacological benefits, such as managing diabetes, cardiac protection, and neuroprotection. This study aims to develop niosomes (NS) containing BS, utilizing cholesterol as the lipid and Tween 80 as the stabilizer. The research focuses on designing and evaluating both conventional BS-NS and hyaluronic acid (HA) modified NS (BS-HA-NS) to enhance the specificity and efficacy of BS within cardiac tissue. The resulting niosomal formulation was spherical, with a size of about 158.51 ± 0.57 nm, an entrapment efficiency of 93.56 ± 1.48 %, and a drug loading of 8.07 ± 1.62 %. To evaluate cytotoxicity on H9c2 heart cells, the MTT assay was used. The cellular uptake of BS-NS and BS-HA-NS was confirmed by confocal microscopy on H9c2 cardiac cells. Administering BS-NS and BS-HA-NS intravenously at a dose of 10 mg/kg showed the ability to significantly decrease the levels of cardiac troponin-I (cTn-I), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and lipid peroxidation (MDA). Tissue histopathology indicated a substantial potential for repairing cardiac tissue after treatment with BS-NS and BS-HA-NS and strong cardioprotection against ISO induced myocardial tissue damages. Thus, enhancing BS's therapeutic effectiveness through niosome surface modification holds promise for mitigating cardiac damage resulting from CT.

Unlocking the miRNA-34a-5p/TGF-β and HMGB1/PI3K/Akt/mTOR crosstalk participate in the enhanced cardiac protection of liraglutide against isoproterenol-induced acute myocardial injury rat model

Liraglutide (LIRA), a drug used to treat type 2 diabetes mellitus that belongs to the glucagon-like peptide-1 class, has recently drawn attention for its potential cardioprotective properties because of its anti-oxidative and anti-inflammatory properties. This current investigation was designed to assess the impact of LIRA on myocardial injury induced by isoproterenol (ISO). The experiment included 24 male Wistar rats in total, and they were divided into four groups: Control, LIRA (200 µg/kg/12 hrs., S.C.), ISO (85 mg/kg, S.C.), and ISO + LIRA. To assess the results, various biochemical and histopathological analyses were carried out. The findings showed elevated serum enzyme levels, a sign of cardiac injury. ISO-treated rats showed an upregulation of oxidative stress and inflammatory biomarkers like MDA, MPO, nitrites, NADPH oxidase, TNF-α, IL-1β, IL-6, 8-Hydroxyguanosine (8-OHdG), and TGF-β, as well as altered gene expressions like TLR-1 and miRNA-34a-5p. According to western blotting analysis, protein levels of AKT, PI3K, and mTOR were obviously enhanced. Additionally, ISO-treated samples showed altered tissue morphology, elevated caspase 3, and decreased Bcl2 concentrations. The levels of these dysregulated parameters were significantly normalized by LIRA therapy, demonstrating its cardioprotective function against ISO-induced myocardial injury in rats. This protective mechanism was linked to anti-inflammatory properties, redox balance restoration, and modulation of the miRNA-34a-5p/TGF-β pathway.